Each line is one set: `set_name<TAB>description<TAB>item1<TAB>item2<TAB>...`. Lines with fewer than 3 tab-separated columns or empty set names are skipped.
Examples
tmp <- tempfile(fileext = ".gmt")
writeLines(c("SetA\tdesc\tGENE1\tGENE2\tGENE3",
"SetB\tdesc\tGENE2\tGENE3\tGENE4"), tmp)
ds <- load_gmt(tmp)
ds@set_names
#> [1] "SetA" "SetB"